CRT MONITOR cathode-ray tube

Contents

•Cathode Ray Tube (CRT)

-Advantages of CRT

-Disadvantages of CRT

- How CRTs work & display?•Liquid Crystal Display(LCD)

-Advantages of LCD

-Disadvantages of LCD

- How LCD work & display?•Plasma

-Advantages of Plasma

-Disadvantages of Plasma

- How Plasma work & display?

The cathode rayed tube can easily increase the monitor’s brightness by reflecting the light.

They produce more colours The Cathode Ray Tube monitors have lower price rate than the LCD

display or Plasma display. The quality of the image displayed on a Cathode Ray Tube is superior to

the LCD and Plasma monitors. The contrast features of the cathode ray tube monitor are considered

highly excellent.

Advantages of CRT

BACK

They have a big back and take up space on desk. The electromagnetic fields emitted by CRT monitors constitute a health

hazard to the functioning of living cells. CRTs emit a small amount of X-ray band radiation which can result in a

health hazard. Constant refreshing of CRT monitors can result in headache. CRTs operate at very high voltage which can overheat system or result in

an implosion . Within a CRT a strong vacuum exists in it and can also result in a

implosion . They are heavy to pick up and carry around.

Disadvantages of CRT

BACK

A CRT monitor contains millions of tiny red, green, and blue phosphor dots that glow when struck by an electron beam that travels across the screen to create a visible image. In a CRT monitor tube, the cathode is a heated filament. The heated filament is in a vacuum created inside a glass tube. The electrons are negative and the screen gives a positive charge so the screen glows.

How CRTs work & display?

BACK

Plasma

Larger viewing angle, 160º compared to LCD 40º & rear projection 120º. (Allows a larger audience to be able to view the image reproduction)

No projection throw distance limitations. All plasma display units are considerably thinner in width than the cathode

ray tube monitors. Most plasma display units are either free standing or can be mounted on a

ceiling or wall. The plasma display units has a clearer image, brighter viewing angle,

better colour quality and higher contrast ratio than the CRT and LCD display units.

Advantages of plasma

BACK

Compared to other display units the plasma display unit has a very short life span, the manufactures estimate the life span to be around 20,000 hours to 30,000 hours (at a rate of 4 hours of TV a day that gives only 13.7 years).

As your plasma display unit gets older its brightness gets dimmer. Plasma display units are considerably more expensive than cathode ray

tube monitors. Plasma display units must be handled carefully because they are a very

fragile display unit.

Disadvantages of plasma

BACK

The television lights up thousands of tiny dots with a high-energy beam of electrons. In most systems, there are three pixel colours -- red, green and blue which are evenly distributed on the screen. By combining these colours in different proportions, the television can produce the entire colour spectrum. The phosphors on the screen of the plasma enhances the viewing pleasure.

How does it work & display

BACK

LCDLiquid Crystal Display

The sharpness of a LCD display is maximum. Zero geometric distortion at the native resolution of the panel. High peak intensity produces very bright images. Best for brightly lit

environments. Screens are perfectly flat. Thin, with a small footprint. Consume little electricity and produce little heat The LCD display unit is very light and can be put anywhere or moved anywhere

in the house.

Advantages of LCD

BACK

After a while the LCD display the some of the pixels will die you will see

a discoloured spot on a black spot on the display.

The cost of a LCD is considerably at a high price.

The LCD display will have slow response times.

The LCD display has a fixed resolution display and cannot be changed.

LCDs use analog interface making careful adjustment of pixel

tracking/phase in order to reduce or eliminate digital noise in the image.

The viewing angle of a LCD display is very limited due to the Automatic

pixel tracking/phase controls.

Disadvantages of LCD

BACK

Liquid crystal displays work by the tiny pixels on the screen showing more

than 20,000,000 colours an LCD screen is a multilayered, sideways

sandwich. A fluorescent light source, known as the backlight. This light

passes through the first of two polarizing filters. The polarized light then

passes through a layer that contains thousands of liquid crystal pixels arrayed

in tiny containers called cells. The cells are, in turn, arrayed in rows across

the screen; one or more cells make up one pixel. Electric leads around the

edge of the LCD create an electric field that twists the crystal molecule,

which lines the light up with the second polarizing filter and allows it to pass

through it.

How does it work & display

BACK

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